Diamond



FIG. 1 is a top plan view of the claimed design;

FIG. 2 is a bottom plan view thereof;

FIG. 3 is a head view thereof;

FIG. 4 is a point view thereof; and,

FIG. 5 is a side elevational view, the opposite side view being a mirror image. 

CLAIM The ornamental design for a diamond, as shown and described. 